Type II diabetes mellitus (DM) is characterized by hepatic and peripheral insulin resistance. Troglitazone and Metformin are two insulin-sensitizing agents that reduce hepatic glucose production and improve glucose control. The effects of these agents on whole-body glucose production, adipose tissue lipolytic rates, insulin sensitivity, and body composition will be assessed in 24 individuals with insulin-requiring type II DM who undergo 12 weeks of Troglitazone or Metformin therapy.